Thread-controlling device for sewing-machines.



No. 680,!92. PatentedAug. 6, |90I.

B. J. BERGMAN. THREAD CONTRLLING DEVICE FUR SEWING MACHINES.

(Application led Apr. 24, 190 0.)

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No. 680,!92. Patented Aug. 6, I90l.

B. J. BERGMAN.

THREAD CONTROLLING DEVICE FUR SEWING MACHINES.

(Applic'ation filed Apr. 24, 1900.) (No Model.) 2.S heets-$heet 2.

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I UNITED STATES PATENT EEICE.'

BENJAMIN J. EEEGMAN, oE NEW YORK, N. Y.

THREAD-CONTROLLING DEVICE FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 680,192, dated August6, 1901.

Application iiled April 24, 1900. Serial No. 14,099. (No model.)

T all whom t may concern.-

Beit known that 1, BENJAMIN J. BERGMAN, of New York, county and State ofNew York, have invented an Improvement in Thread- Controlling Devicesfor Sewing-Machines, of which the following description, in connectionwith the accompanying drawings, is a specification, like letters andfigures on the drawings representing like parts.

The invention to be herein described is applicable more especially tobuttonhole-sew# ing machines of the class represented in United StatesPatent No. 494,280,dated March 28, 1893.

In accordance with this invention I have applied to the rotatingneedle-bar a pull-off device and thread-guard, said device pulling odfrom the thread-suppl y a sufficient quantity of thread just as orbefore the buttonhole is completed, and the stitch-forming mechanism isstopped withv its needle withdrawn from the work, said slack threadbeing freely supported by the guard and given up to the complementalstitch-forming mechanism coperating with the eye-pointed needle whensaid needle is again started to make its rst stitch in anotherbuttonhole to be made. In the machine to be herein described,as providedfor in the patent referred to, the stitch-forming mechanism carried by astitch-frame is started into operation at Yone end of the buttonhole andoveredge stitches are made completely about the edge of the buttonhole,and the buttonhole having been completed by a relative change of,position of the stitch-frame and clothframe provided with the usualcloth-clamp the stitch-forming mechanism is put into its inoperativeposition or stopped with the needle elevated, and thereafter while thestitch-forming mechanism is inoperative the relative positions of thestitch-frame and clamp-frame are changed to bring into its operative-position the buttonhole-cutting mechanism, and in such position oftheparts the machine is stopped. The operator puts the material in whichthe new buttonhole is to be cut in the clamp and closes the clamp, whichstarts the machine, causing the cutter to descend and cut thebuttonhole. This is done at a high speed of the machine and the highspeed is continueduntil a change is eected in the relative positions ofthe stitch-frame and cloth-frame to put the stitch-forming mechanism inposition to commence stitching a cut buttonhole, all as in said patent.On the arrival of the stitch-forming mechanism in its position to bestarted the stitch-forming mechanism is started automatically intooperation, and

thereafter the slower speed of the machine controls throughout thestitching of the buttonhole. Herein the needle-thread pulled off fromthe tension device and stored up during the stitching of the buttonholeabout the eye and from the eye to the finished end is freely supportedby the thread-guard and given up to the stitch-forming mechanism at inillustrated it consists, essentially, of an y arm having thread-eyes anda collar and a thread-guard to freely support the thread, the collarbeing applied to the upper end of the rotatable needle-bar.

Figure l represents a top or plan View of a suiiicient portion of abuttonhole-sewing machine to enable my invention to be understood. Fig.2 is a detail showing a portion of the usual cloth-clamp. Fig. 3 is apartial right-hand side view of the apparatus shown in Fig. 1. p showingthe top of the needle-bar and the tension device with the pull-off indifferent positions. v

Referring to the drawings, a represents the overhanging arm of astitch-frame. a. shows part of the clamp-frame; b', the needle-bar; d2,the complete gear on the needle-bar; b2, an eye-pointed thread-carryingneedle; 22, one of the levers of a cloth-clamp; m', a clamping-foot ofsaid lever; 23, a pivot for the lever 22; b3, a take-up; b4, a tensiondevice for the needle-thread, it being acted upon by a spring b5, theforce of which is controlled by a nut bs. These devices are all commonto the patent referred to. Coperating with this Fig. 4 is a diagrammaticY'view' IOO o needle-bar h' out through an opening 17, comeye-pointedneedle b2 in the formation of overedge stitches for buttonholes isl inpractice in said patent, and the stitch-frame will carry,

as provided for in that patent, buttonholecutting mechanism actuated asprovided for in said patent, and the' stitch-frame in the operation ofstitching a buttonhole will vbe run at one speed and after thebuttonhole has been finished and the stitch-termin g mechanism hasbeen'stopped, so that it no longer stitches, a faster-speed mechanismwill come into operation to impart a faster motion to the parts duringthe time that the relative positions ofthe stitch-frame and clamp-frameare being changed to put the buttonhole-cutting mechanism into propercooperative relation to the clamp that the latter may receive newmaterial and the buttonhole be cut, and the stitch-traine andcloth-frame may then be returned into a position to put thestitch-forming mechanism into positionv to be again started to commencethe stitching of a new buttonhole.

I will now particularly describe my additions to the old parts hereinalluded to.

As I have herein chosen to illustrate my invention the collar 10,01 thearm 12, constituting one form of pull-off, is slipped over the end ofthe needle-bar b and secured in position thereon by a set-screw 13. Thearm has, as-shown, (see Fig. 3,) three thread-holes, through either ofwhich maybe passed the needle-thread 14 under the control of the takeupbe', the thread coming to the take-up from a suitable tension device, asb4. The arm shown has two like thread-guards 16, which preferably extendlengthwise of the arm on one side thereof, being secured at or near theend of the arm and also at or near the collar. This thread-guardextending lengthwise of the arm serves to freely support the slackthread after it is drawn from the thread-supply. The needle-thread fromthe take-up is led through one of the thread-holes in the arm, andthence down through the hollow mon to said patent, at the lower end ofsaid ierle-bar, and through the eye of the nee- Figs. 1 and 3 by fulllines show the pull-off in the position it occupies when the stitchframeand cloth-frame are in position to receivematerial that the cutter mayact to cut the material. The dotted-line position, Fig. 1is thatoccupied by the pull-off when the stitching of the buttonhole is to becommenced, the full-line position, Fig. 4, being that occupied by thepull-off as the stitching of the buttonhole is completed. Viewing Fig.1, the position designated by dotted lines is that occupied by thepull-off when the stitch forming mechanism is about to be rholding thethread taut.

started to commence the Astitching of 'a buttonhole, and it will be seenthat there is slack thread (designated by dottedlines) between theend-of the pull-0E and the take-up.

This rslack thread freely supported on the forming device, so that wit-hsuch slack thread y vstored up there is no possibility of the firststitch in making the buttonhole not being made properly.

During the operation of stitching the buttonhole the stitch-frame andcloth-frame have imparted to them relative movements at a predeterminedspeed, the stitch forming mechanism making stitches along one side ofthe buttonhole about the eye thereof and then along the opposite sideand finishing the buttonhole, and during this stitching of thebuttonhole and finishing the same the pull-oft rotates with theneedle-bar and stops in the full-line position, Fig. 4, so that theneedlethread is made to occupy the position shown by the line lli-thatis, it is led from the takeup or tension about the collar and along theside of the arm of the pull-off. In this position the needle-bar islifted and the stitchlforming mechanism, the buttonhole having beencompleted, is stopped with the pull-off At this point the fast-speeddriving mechanism for the stitchframe, fully described in said patent,comes into operation and the stitch-frame is moved in the direction ofthe'arrow 7, Fig. 1, causing the needle-thread to be bent over thefinger 2O of the cloth-clamp, as represented in Fig. 3, the movement ofthe stitch-frame being continued until the usual buttonhole-cutter (notshown, but commonto said patent) is put into operative position withrelation to the open cloth-clamp. The cutting mechanism having beenbrought into operating position, the fast-speed motion is thrown out ofoperation and the stitch-frame is left stationary with the needle-baryet elevated, and during this motion of the stitch-frame the usualsector for rotating the stitch-forming mechanism has turned .theneedle-bar b', so that the pull-oft occupies the position shown by fulllines, Fig. l, and as the cutting mechanism comes into position to havethe material put into the clamp the pull-oft' has given up some slackthread which has been pulled through the needle by the action of theneedle-thread between the point of the needle and the work against thefinger 20. When the pull-od occupies the full-line position, Fig. 1, theoperator cuts the needle-thread close to the work, puts the new materialin the open clamp, and closes the clamp. The closing of the clamp putsautomatically into operation the usual fast-speed mechanism common tosaid patent, and by the time that ,-thefcutter begins to descend thepull-0E occupies the position shown by dotted lines,

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Fig. 4. The cutter .operates quickly and rises and the fast-speedoperating mechanism continues until the stitch-forming mechanism hasbeen brought into its starting position, at which time the pull-offoccupies the dotted-line position, Fig. l. Viewing Fig. l, it will beseen that the thread leads directly from the take-up to and through theeyes at the end of the pull-oif and thence into the hollow needle-bar.The starting position of the pull-off when the rst stroke of the needieis made in commencing to stitch a buttonhole leaves a'. considerableamount of slack thread sufficient to always insure that the under orcomplemental stitch-forming mechanism engage the loop of needle-threadand secure the needle-thread in the work. The ,stitch-forming mechanism.is started while a slower speed is available for moving thestitch-frame, and during this stitching operation the pull-off movesfrom its dotted-A line position, Fig. l, into the full-line position,Fig. 4, said full-line position showing the position occupied by thepull-off and stitching mechanism when the last stitch of the buttonholeis completed,'the stitching mechanism at the rise of the needle from thepoint where it made its last stitch in the buttonhole being suspendedwhile the cutting operation takes place, as hereinbefore described.

Having described my invention, what I claim as new, and desire to secureby Letters Patent, is

l. In a buttonhole-sewlng machine, stitchforming mechanism comprising aneedle-bar, means to rotate said needle-bar, an attached pull-01T havinga thread-receiving hole near its end to receive the needle-thread on itsWay to the needle-bar, and an attached thread-guard exten-dinglengthwise of the pull-off and on which the thread is adapted to befreely supported, the rotation of the needle-bar in stitching abuttonhole pulling off a supply of thread with which to commence thenext buttonhole.

2. In a buttonhole-sewing machine, stitchforming mechanism comprising aneedle-bar, means for rotating said bar, an attached pullo having aseries of thread-receiving eyes near its end and a thread-guardconnected to said pull-off, said guard extending lengthup at thecommencement of the next buttonv hole.'

et. A hollow needle-bar, a pull-off adjustably attached to saidneedle-bar andv having a thread-receiving eye near its outer end tothrough said needle-bar, and means to rotate said needle-bar during thestitching operation to draw 0E slack thread from the thread-'supplyduring stitching and to give up said'slack thread during a reversemovement of said needle-bar to put it in position to resume stitching ofanother buttonhole, and a threadguard extending on one side ofA thepull-off and on which the thread is adapted to be supported.

5.A In a sewing-machine, the combination with the stitch-formingmechanism comprising a needle-bar, of a pull-od axially adjustable onsaid needle-bar and. having a series of thread eyes or passages for thethread 1ocated at different distances from the needlebar andthread-guards connected to said pulloff and movable therewith and onwhich the thread is adapted to be freely supported.

6. In a sewing-machine, the combination.

with the stitch-forming mechanism comprising a needle-bar, of a pull-offcarried by said needle-bar, and having a thread-eye, and thread-guardsextending lengthwise of and above and belowthe pull-od between which thethread is adapted to be freely supported. In testimony whereof I havesigned my name to this specification in the presence of two subscribingwitnesses.

BENJAMIN J. BERGMAN.

Witnesses:

GEO. W. GREGORY, MARGARET A. DUNN.

7o receive the thread preparatory to its passage

